Surgical relevance of anatomic variations of the right hepatic vein

Table 1 Variations of the right hepatic vein at the hepatocaval junction according to the classification of Nakamura and Tsuzuki[4]

Type	Description	Trinidad and Tobago (%)	India[16] (%)	Japan[4] (%)	China[17]1 (%)	Turkey[18]1 (%)	Slovenia[6] (%)	France[19] (%)	Vietnam[39] (%)
		CT	Cadaver	Cadaver	CT	CT	Cadaver	Cadaver	Cadaver
I	No tributaries within 1cm of the IVC	83/118 (70.3)	82/100 (82)	51/83 (61.4)	162/200 (85)	40/100 (40)	85/110 (77.3)	32/64 (50)	18/20 (90)
II	One tributary within 1 cm of IVC; IIa: Right superior vein; IIb: Right antero-superior vein	24/118 (20.3)	10/100 (10)	19/83 (22.8)	17/200 (8.5)	57/100 (57)	NS	20/64 (31.3)	0
III	Both right superior and right antero-superior veins join within 1cm of IVC	6/118 (5.1)	4/100 (4)	8/83 (9.6)	6/200 (3)	3/100 (3)	NS	10/64 (15.6)	0
IV	Two veins empty directly into IVC: (1) Right hepatic with a branch of right antero-superior vein; and (2) Independent right superior vein	5/118 (4.2)	4/100 (4)	5/83 (6)	15/200 (7.5)	0	NS	2/64 (3.1)	2/20 (10)

¹Different classifications used. Classified retrospectively by extrapolating from published images and raw data.

CT: Computed tomography; IVC: Inferior vena cava; NS: Not specified.

Table 2 Prevalence of accessory right hepatic veins in selected countries

Country	Methodology	None (SRHV only) (%)	MRHV (%)	IRHV (%)
Trinidad and Tobago	Imaging (CT)	60/118 (51)	5/118 (4)	53/118 (45)
Global prevalence		3343/4657 (71.8)	145/2652 (5.5)	1361/4657 (29.2)
P value		< 0.0001	0.562	0.0002
Poland[21]: 1975	Cadaveric	79/93 (84.9)	NS	14/93 (15.1)
France[22]: 1978	Cadaveric	62/80 (77.5)	NA	18/80 (22.5)
Japan[4]: 19811	Cadaveric	32/83 (38.6)	20/83 (24.1)	31/83 (37.3)
France[23]: 1981	Cadaveric	79/100 (79)	NS	21/100 (21)
Japan[24]: 1983	Ultrasound (operative)	242/269 (90)	2/269 (0.7)	27/269 (10)
Korea[25]: 1987	Ultrasound	67/124 (54)	NA	57/124 (46)
France[19]: 19881	Cadaveric	32/64 (50)	11/64 (17.2)	28/64 (43.8)
England[26]: 1990	Imaging (MRI)	63/82 (76.8)	0	19/82 (23.2)
France[27]: 1993	Cadaveric	111/125 (88.8)	NA	14/125 (11.2)
United States[28]: 1995	Imaging (CT)	62/69 (89.9)	1/69 (1.5)	6/69 (8.7)
Taiwan[29]: 1997	Imaging (US)	306/400 (76.5)	22/400 (5.5)	72/400 (18)
Slovenia[6]: 2000	Cadaveric	79/110 (71.8)	8/110 (7.3)	31/110 (28.2)
Central India[16]: 2001	cadaveric	96/100 (96)	0	4/100 (4)
Turkey[18]: 20041	Imaging (CT)	53/100 (53)	19/100 (19)	28/100 (28)
Turkey[30]: 2004	Imaging (CT)	243/308 (78.9)	NA	65/308 (21.1)
United States[31]: 2004	Imaging (CT)	40/65 (61.5)	0	25/65 (38.5)
Turkey[32]: 2005	Imaging (CT)	27/52 (51.9)	0	25/52 (48.1)
Germany[33]: 2005	Imaging (CT)	30/55 (54.5)	NA	25/55 (45.5)
Turkey[8]: 2007	Imaging (CT)	764/1120 (68.2)	NA	356/1120 (31.8)
Japan[34], 20081	Cadaveric	0/60	18/60 (30)	52/60 (86.7)
Scotland[35]: 20101	Cadaveric	0/18	2/18 (11.1)	16/18 (88.9)
South China[17]: 2012	Imaging (CT)	158/200 (79)	0	42/200 (21)
Japan[2]: 2016	Imaging (CT)	46/100 (46)	20/100 (20)	34/100 (34)
South Korea[36]: 2017	Imaging (CT)	196/360 (54.4)	22/360 (6.1)	164/360 (45.6)
Northern India[37]: 2019	Imaging (CT)	458/500 (91.6)	0	185/500 (37)
Vietnam[39]: 2020	Cadaveric	18/20 (90)	0	2/20 (10)

¹Different classification used in this publication. Classified by extrapolated from raw data, images and/or descriptions.

CT: Computed tomography; IRHV: Inferior right hepatic vein; MRHV: Middle right hepatic vein; MRI: Magnetic resonance imaging; NA: Parameter not assessed specifically in this study; NS: Result not specified in this study; SRHV: Superior right hepatic vein; US: Ultrasound.